(a) Field of the Invention
The present invention relates to a wire grid polarizer. More particularly, the present invention relates to a method of manufacturing a wire grid polarizer that can be produced in a large area and that can perform a continuous process using a roll stamp.
(b) Description of the Related Art
A wire grid polarizer is formed with a substrate and metal lines having a high aspect ratio and that are formed on the substrate. The metal lines are separated and are arranged in parallel. When an arrangement cycle (pitch) of the metal lines is fully smaller than a wavelength of incident light, in the incident light, a polarizing component parallel to the metal lines is reflected, and a polarizing component perpendicular to the metal lines is transmitted. The wire grid polarizer converts incident light to straight polarized light using such a phenomenon.
In the wire grid polarizer, a pitch of the metal lines is approximately 40 nm to 200 nm, a width of each metal line is approximately 20 nm to 100 nm, and a height of each metal line is approximately 20 nm to 200 nm. The metal lines are made of a metal such as aluminum, tungsten, or titanium.
As a conventional method of manufacturing a wire grid polarizer, several technologies such as an exposure technology and a nanoimprint technology are well known. However, the exposure technology has a limitation in an expensive apparatus or reduction of a width of a metal line, and nanoimprint technology can perform micropatterning of tens of nanometers, but has difficulty in mass production.
FIG. 16 is a schematic diagram illustrating a conventional method of manufacturing a wire grid polarizer using nanoimprint technology.
Referring to FIG. 16, nanoimprint technology includes a process of forming a mask layer 345 that is made of an organic material or an organic-inorganic complex material on a metal film 310, pressing and hardening the mask layer 345 with a stamp 330 in which a nanostructure body 320 is formed, patterning the mask layer 345 into an etching mask 340, dry etching the metal film 310, and patterning the metal film 310 into metal lines 315.
In such nanoimprint technology, it is difficult to control a remaining layer in a large area process and a continuous process using a roll stamp in view of a characteristic of a pressing process.
For example, as a substrate 350 is formed in a large size, a remaining layer (a portion that is not patterned but remains) 346 may occur in the etching mask 340 by surface non-uniformity (flatness deterioration) of the substrate 350, and the remaining layer 346 causes a pattern failure of the metal lines 315. Further, because the etching mask 340 that is made of an organic material is easily damaged in a process of ion etching the metal film 310, there is a limitation in enhancing an aspect ratio of the metal line 315.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.